In the conventional writing instrument, many products and inventions are known which are made in consideration of reduction of fatigue of finger gripping the grip section and slip resistance. One such example is Japanese Patent Application Laid-Open Publication No. 05-177,979. Claim 1 of this Publication reads as “an auxiliary tool for holding a writing tool which can be used in combination with a writing tool 1, comprising a first ring 2 having an inner diameter which can be engaged fast with the writing tool 1 and a peripheral shape larger than a cross section of the writing tool 1, which can be fixed at an optional position of the tool 1 and a holder 3 including an annular part 4 which can be engaged with the writing tool 1 idly and has an inner diameter slightly smaller than the outer diameter of the ring 2 and a member 6 (10) which can be grasped by a palm relating to the annular part 4, the holder 3 being able to idly engage with the writing tool 1 at a position higher than the ring 2”. That is, this conventional device aims at reducing fatigue of hand, arm and shoulder by providing a support part other than finger.
However, a certain degree of gripping force is required for the thumb and other fingers gripping the grip section so that the grip section will not slip. The normal way for supporting the writing instrument only at three points by the thumb, the index finger and the middle finger is not enough for reducing the loads to the thumb and other fingers because excessively large force is unconsciously exerted to the thumb and other fingers.
Moreover, the attempt for attaching a support member to the barrel so as to be held in the palm of the hand tends to jeopardize portability of the writing instrument and easy handling thereof. That is, the conventional writing instrument of the type just mentioned is difficult to be put in a pocket, a pencil case, etc. When gripping the writing instrument, the direction for gripping the barrel is forcibly determined.